Room-temperature preparation and dielectric properties of amorphous Bi3.95Er0.05Ti3O12 thin films on flexible polyimide substrates via pulsed laser deposition method

Bi3.95Er0.05Ti3O12 (BErT) thin films were prepared on flexible polyimide (PI) substrates at room temperature by pulsed laser deposition. These BErT thin films deposited under low oxygen pressures are dense, uniform, and crack-free with an amorphous structure. The highly flexible thin film with a thickness of about 160 nm deposited under 3 Pa oxygen pressure shows excellent dielectric characteristics, such as a dielectric constant of 51 and a dielectric loss of 0.025, and a maximum capacitance density of 237 nF/cm2 at 1 kHz. When it is curved at different curvature radii (by applying external deformation), the thin film still remains superior dielectric performance. In addition, the thin film also shows good dielectric aging characteristic (or thermal stability) and high optical transparency. BErT thin films can find applications in flexible optoelectronic devices and embedded capacitors.